The potential problems caused by increasing concentrations of greenhouse cases, such as CO2 and methane, in the atmosphere have been the source of growing concern over the past decade. Although still controversial, the identification of human activity as the primary source of the increased levels of these gases has gained greater and greater acceptance in scientific and political circles. (See, e.g., Solomon, S., et al. (eds.), “Chapter 7. Couplings Between Changes in the Climate System and Biogeochemistry”, Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, N.Y., USA: Cambridge University Press. ISBN 978-0-521-88009-1 (2007), the disclosure of which is incorporated herein by reference). For example, measurements from Antarctic ice cores show that just before industrial emissions started, and for the preceding 10,000 years, atmospheric CO2 levels remained constant at about 280 ppm. However, since the beginning of the Industrial Revolution, the concentrations of many of these greenhouse gases have increased. In particular, the concentration of CO2 has increased by about 100 ppm (i.e., from 280 ppm to 380 ppm) over this period of time. Moreover, the first 50 ppm increase took place in about 200 years, from the start of the Industrial Revolution to around 1973, while the next 50 ppm increase took place in only 33 years, from 1973 to 2006. (See, e.g., Le Treut, et al., Historical Overview of Climate Change Science In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., et al., (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, N.Y., USA (2007), the disclosure of which is incorporated herein by reference.)
Moreover, the recent focus on greenhouse gases has not had a significant impact on reducing CO2 emission or the concentration of CO2 in the atmosphere. Indeed, there has been a sharp acceleration in CO2 emissions since 2000 of greater than 3% per year, up from an average increase of only ˜1.1% per year during the 1990s. (See, Raupach, M. R. et al. Proc. Nat. Acad. Sci. 104(24): 10288-10293 (2007), the disclosure of which is incorporate herein by reference.) In comparison, methane has not increased appreciably over this time frame, and nitrous oxide (N2O) has increased by a constant rate of only ˜0.25% per year. (See, IPCC Special Report on Emissions Scenarios, Chapter 3, (2000), the disclosure of which is incorporated herein by reference.) What is more, over the 2000-2010 interval China is expected to increase its CO2 emissions by 600 Mt, largely because of the rapid construction of old-fashioned power plants in poorer internal provinces. (See, Auffhammer, M., et al., Journal of Environmental Economics and Management 55 (3): 229-247 (2008), the disclosure of which is incorporated herein by reference.)
From a climate change perspective, the increase in CO2 concentration is of particular concern because its radiative impact is many factors higher than the next significant greenhouse gas. For example, CO2 has a radiative force of 1.46 W/m2, while methane has a radiative force of only 0.48 W/m2. (Radiative force is a measure of the increase in the radiative energy available to Earth's surface and to the lower atmosphere as the result of the presence of a particular molecule. See, Kiehl, J. T., Bulletin of the American Meteorological Society 78 (2): 197-208, the disclosure of which is incorporated herein by reference.) In addition, recent research suggests that the atmospheric lifetime of CO2 may be substantial higher than previously suspected. The atmospheric lifetime of a species measures the time required to restore equilibrium following an increase in its concentration in the atmosphere. Individual atoms or molecules may be lost or deposited to sinks such as the soil, the oceans and other waters, or vegetation and other biological systems, reducing the excess to background concentrations. The average time taken to achieve this is the mean lifetime. CO2 has a variable atmospheric lifetime, and cannot be specified precisely. (See, Solomon, S, et al. eds., IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge, United Kingdom and New York, N.Y., USA: Cambridge Press, ISBN 978-0521-88009-1, (2007), the disclosure of which is incorporated herein by reference.) It has often incorrectly been stated that CO2 has an atmospheric lifetime of only a few years because that is the average time for any CO2 molecule to stay in the atmosphere before being removed by mixing into the ocean, or by photosynthesis or other processes. However, this ignores the balancing fluxes of CO2 emission into the atmosphere from the other reservoirs. It is the net concentration change of the various greenhouse gases by all sources and sinks that determines atmospheric lifetime, not just the removal processes. For example, recent work indicates that recovery from a large input of atmospheric CO2 from burning fossil fuels will result in an effective lifetime of tens of thousands of years. (See, e.g., Archer, D., Journal of Geophysical. Research 110 (C9): C09S05.1-009S05.6 (2005); and Caldeira, K., et al., Journal of Geophysical Research 110 (C9): C09S04.1-009S04.12 (2005), the disclosures of which are incorporated herein by reference.)
Production of CO2 globally has been brought into sharp focus in recent years through declarations such as the Kyoto accord, and also by industry leaders committing to tangible reductions in CO2 emissions. In essence, the Kyoto accord distilled a global problem into a national one, by setting emission targets for greenhouse gases compared with a baseline 1990 level, with a view to pegging and reducing global emissions. How individual nations, economic communities (such as the EU) and industry react to the growing pressures to reduce CO2 is still to be formulated and ratified. A key element in the debate is whether specific industries should be targeted and whether CO2 trading should be allowed across national boundaries and/or industries.
One industry that has been the early target of regulation is the energy sector. Within the energy sector, petroleum refining is by far the largest carbon emitter for the petroleum and coal products industry, accounting for around 5% of all CO2 emissions relating to the processing of petroleum products (over 90% comes from the burning of petroleum products). The petroleum refining industry uses almost 30 percent of all energy used in manufacturing and emits over 20 percent of the carbon dioxide. (Battles, S., Energy Information Administration, “1994 Manufacturing Energy Consumption Survey'”, “Monthly Refinery Report” for 1994, and Emissions of Greenhouse Gases in the United States 1998, the disclosures of which are incorporated herein by reference.) As a result, petroleum refining has come under increasing scrutiny from regulators. For example, the state of California is developing rules around their Global Warming Solutions Act (AB32) and is looking for ways to significantly reduce CO2 production. Refineries and power plants are the largest targets of this rule making. In addition, a recently filed suit, led by New York Attorney General Andrew Cuomo, and filed on behalf of a dozen states including California, Connecticut, Delaware, Massachusetts, Maine, New Hampshire, New Mexico, Oregon, Rhode Island, Vermont, and Washington, as well as the District of Columbia and the City of New York, charges that the Environmental. Protection Agency violated the federal Clean Air Act by refusing to issue standards, known as new source performance standards, for controlling global warming pollution emissions from oil refineries. (See, Chemical & Engineering News Vol. 86 No. 35, 1 Sep. 2008, “Challenging EPA”, p. 11, the disclosure of which is incorporated herein by reference.) The suit seeks to force the EPA to control oil refinery emissions of greenhouse pollution and to order the agency to adopt the standards. Among other things, the suit contends that about 15 percent of US industrial emissions of carbon dioxide come from crude refineries, which burn some oil as they make products like gasoline and jet fuel. Likewise, Australia has many industries that are emissions-intensive and trade-exposed, so-called EITE industries. Emissions-intensive means the costs of their carbon emissions under an emissions trading scheme will have a material impact on their cost structure and profitability. Among the industries targeted by the Australian government by this program is oil refining, which the industry argues may create a price for carbon that makes oil refining in the country uncompetitive in a global market.
In addition, the public has put strong pressure on the local and national governments to prevent the development of new refineries. These efforts have been largely successful in the United States, where no major refinery has been built since Marathon's Garyville, La. facility in 1976. Additionally, many refineries (over 100 since the 1980s) have closed due to obsolescence and/or merger activity within the industry itself. There is a growing awareness that this lack of development will need to be addressed, particularly as environmental restrictions and the pressure to prevent construction of new refineries is one of the contributing factors to the rising price of refined fuels in the United States. (Hargreaves, S., “Behind high gas prices: The refinery crunch”, CNNMoney.com Apr. 17, 2007, the disclosure of which is incorporated herein by reference.) However, there is an increasing recognition that for the petroleum refining industry to survive refineries must be modified to reduce their environmental footprint, including their CO2 emissions.
While several strategies have been proposed to make the petroleum industry more efficient, thus far these systems have focused only on specific and isolated segments of the petroleum lifecycle. For example, proposals have been made to address the inefficiencies of power generation at refineries, either by using lower carbon fuels for power generation, or by using gasification, which allows for heavy residue destruction and relatively easy CO2 capture and other environmental benefits. However, over half of petroleum refining carbon emissions are generated from petroleum by-products (chiefly still gas and petroleum coke) that are further processed and used as lower grade fuels. Thus far no economically practical systems have been proposed to address the efficiency of the overall petroleum industry, including how to address these “by-product” carbon sources. Accordingly, an integrated system to manage CO2 emission from the processing and use of these “by-product” fuels, and to provide a more efficient overall petroleum lifecycle is needed.